Intracellular modifiers of integrin alpha 6p production in aggressive prostate and breast cancer cell lines

Apollo D. Kacsinta, Cynthia S. Rubenstein, Isis C Sroka, Sangita Pawar, Jaime M. Gard, Raymond B Nagle, Anne E Cress

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Cancer metastasis is a multi-step process in which tumor cells gain the ability to invade beyond the primary tumor and colonize distant sites. The mechanisms regulating the metastatic process confer changes to cell adhesion receptors including the integrin family of receptors. Our group previously discovered that the α6 integrin (ITGA6/CD49f) is post translationally modified by urokinase plasminogen activator (uPA) and its receptor, urokinase plasminogen activator receptor (uPAR), to form the variant ITGA6p. This variant of ITGA6 is a cleaved form of the receptor that lacks the ligand-binding domain. Although it is established that the uPA/uPAR axis drives ITGA6 cleavage, the mechanisms regulating cleavage have not been defined. Intracellular integrin dependent "inside-out" signaling is a major regulator of integrin function and the uPA/uPAR axis. We hypothesized that intracellular signaling molecules play a role in formation of ITGA6p to promote cell migration during cancer metastasis. In order to test our hypothesis, DU145 and PC3B1 prostate cancer and MDA-MB-231 breast cancer cell lines were treated with small interfering RNA targeting actin and the intracellular signaling regulators focal adhesion kinase (FAK), integrin linked kinase (ILK), and paxillin. The results demonstrated that inhibition of actin, FAK, and ILK expression resulted in significantly increased uPAR expression and ITGA6p production. Inhibition of actin increased ITGA6p, although inhibition of paxillin did not affect ITGA6p formation. Taken together, these results suggest that FAK and ILK dependent "inside-out" signaling, and actin dynamics regulate extracellular production of ITGA6p and the aggressive phenotype.

Original languageEnglish (US)
Pages (from-to)335-340
Number of pages6
JournalBiochemical and Biophysical Research Communications
Volume454
Issue number2
DOIs
StatePublished - Nov 14 2014

Fingerprint

Urokinase Plasminogen Activator Receptors
Prostatic Neoplasms
Integrins
Focal Adhesion Protein-Tyrosine Kinases
Cells
Actins
Breast Neoplasms
Cell Line
Paxillin
Plasminogen Activators
Urokinase-Type Plasminogen Activator
Tumors
Neoplasms
Neoplasm Metastasis
Cell adhesion
Cell Adhesion
Small Interfering RNA
Cell Movement
alpha 6p integrin
Ligands

Keywords

  • Actin
  • Cancer
  • Focal adhesion kinase
  • Integrin linked kinase
  • ITGA6
  • uPAR

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Cell Biology
  • Molecular Biology

Cite this

Intracellular modifiers of integrin alpha 6p production in aggressive prostate and breast cancer cell lines. / Kacsinta, Apollo D.; Rubenstein, Cynthia S.; Sroka, Isis C; Pawar, Sangita; Gard, Jaime M.; Nagle, Raymond B; Cress, Anne E.

In: Biochemical and Biophysical Research Communications, Vol. 454, No. 2, 14.11.2014, p. 335-340.

Research output: Contribution to journalArticle

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